coupling of readily available aroylhydrazides with disulfides is developed, in which oxidative expulsion of N2 overcomes the activation barrier between the carboxylic acidderivatives and the products. The reaction produces various thioesters in good to excellent yields with good functional group tolerance. In the reaction, stable and easily available aroylhydrazides are used as acyl sources and the
通过易得的芳酰肼与二硫化物的铜催化的氧化偶联,开发了另一种硫酯化反应,其中N 2的氧化排出克服了羧酸衍生物和产物之间的活化障碍。该反应以良好的收率和优异的官能度耐受性产生了各种硫酯。在该反应中,将稳定且容易获得的芳酰基酰肼用作酰基源,并将相对无味的二硫化物用作S源。机理研究表明,铜盐与氧化剂(NH 4)2 S 2 O 8的反应 可以实现串联过程,包括去质子化,自由基介导的脱氮和CS键形成。
Convenient Route to Thiocarbonates from Alcohols, Thiols, and Triphosgene
作者:Barahman Movassagh、Mohammad Soleiman-Beigi
DOI:10.1080/00397910903457258
日期:2010.11.3
An efficient and simple one-pot, three-component procedure has been introduced for the preparation of various thiocarbonates from thiols, alcohols, and triphosgene in dichloromethane.
A unique catalytic ability of selenium has been developed. When alcohols were allowed to react with diaryl disulfides in the presence of a catalytic amount of selenium under a pressurized carbonmonoxide, S-aryl-O-alkyl thiolcarbonates were obtained in moderate to good yields.
The aminolysis of O-methyl S-aryl thiocarbonates with benzylamines are studied in acetonitrile at −45.0 C. The βX (βnuc) values are in the range 0.62-0.80 with a negative cross-interaction constant, ρXZ = −0.42, which are interpreted to indicate a concerted mechanism. The kinetic isotope effects involving deuterated benzylamine nucleophiles (XC6H4CH2ND2) are large, kH/kD = 1.29-1.75, suggesting that